1. Field of the Invention
This invention relates to bicycle pedals and in particular, to pedals that have a multiplicity of shapes that can accommodate a variety of bicycle shoe cleats. Use of the invention allows cyclists using clip-less pedal systems to cycle on a bicycle fitted with these multiple shaped pedals, when the cyclists have a variety of shoe cleat designs on their shoes.
2. Description of the Prior Art
The continuing development of modern bicycles has resulted today in bikes being available to the general public with a wide variety of pedal designs. Early designs of bicycle pedals consisted of a flat pedal shape with a toe frame that fitted most cyclist's shoes, and included a strap or other connecting means that fixed or fastened the toes of the cyclist's shoes to the pedals. Cycling shoes were typically of a running shoe design and were not specifically designed for cycling. 
In modern bicycle pedal designs this arrangement has been superseded by more precise mechanisms that lock the pedal onto special cleats which are fastened to the base of the cyclist's shoes. These new designs arc called clip-less pedal/cleat designs. Using these new designs, the cyclist mounts the bicycle, places his shoe cleat onto the pedal and the pedal/cleat combination snaps or locks together creating a stable connection between the cyclist's feet and the bicycle pedal.
Various designs of pedal/cleat combinations are presently in use, which either lock rigidly together or allow various degrees of freedom of rotational motion between the pedal and the cleat, depending on the design. Manufacturers of pedals today typically produce pedal designs that require the use of special shoe cleats that lock onto or into their pedals only. This ensures the manufacturer that the cyclist buys their particular combined pedal/cleat products.
Thus modern cyclists require a particular design of matching shoe cleat to be worn on their cycling shoes in order to fit onto the pedals on their bicycles. Due to the better performance and ease of entry and exit of these new pedal/cleat designs, this is now the generally accepted standard in the case of the cyclist's own bicycle. Individual cyclists fit their preferred pedals onto their bicycles and fit the appropriate cleats onto their cycling shoes.
In recent years, there has been increasing interest and use of stationary exercise bicycles and many of the companies that manufacture road bicycles or other exercise equipment have also developed a line of stationary exercise bikes to meet this new demand. However, when these same pedal/cleat combinations developed initially for road bicycles are also used on the stationary cycling machines (or spin-bikes as they are known) which are available in gyms or sports clubs, the cyclist is forced to use the appropriate cleat on his bicycle shoes.
This causes problems, as most cyclists prefer to use a particular brand and design of pedal/cleat combination on their road bicycles, and yet many cyclists have no choice but to  purchase a new set of cycling shoes and install cleats that match the gym's spin bike pedals. Alternatively, cyclists have to bring their own pedals to the gym or exercise club and exchange the pedals on the stationary bike with their own so they can use their own shoes and cleats to exercise. This practice is becoming less and less acceptable to gym instructors who do not want different riders to be changing pedals on their exercise bikes.
Another problem that has arisen on stationary bikes is the breakage of pedal spindles. The pedal spindle is a steel rod that fits inside the pedal center housing with bearings, allowing the pedal to rotate around the spindle. The end of the spindle projects from the side of the pedal and contains a threaded section that is used to connect the pedal to the bicycle crank arm. Breakage of this spindle is extremely rare in outdoor bikes even among world class powerful cyclists and is a phenomenon that occurs quite frequently on stationary bikes probably caused by the higher forces that come to bear on an indoor exercise bike's pedal as explained below.
Part of this breakage problem of spindles is caused by the fact that the frame of a stationary bike is more rigid than the frame of a street or racing bicycle and so there is less ‘give’ or flex available in the frame of the stationary bike. Also, the frame of all exercise bikes sits on the floor supported at four corners by rollers or foot stands. The frame itself is quite rigid when compared to a road bike, since weight is not a premium on an exercise bike. Thus when a rider bears down heavily on one pedal of the stationary bike, the bike does not rotate in the same direction as the pedal load nor does the frame flex, and so all of the extra load is carried in bending by the pedal spindle.
Repeated over-stressing of the spindle in this manner results in spindle failures causing the pedal to suddenly break off the spin bike pedal crank and with the attendant danger of injury to the rider. In some exercise clubs or gyms, pedal spindle breakage is a common occurrence and has increased the costs of maintenance and downtime of equipment and the number of spare parts that must be carried to keep the bikes in good running condition. Exercise clubs are also  very aware of the increased possibility of injury that can occur when one of the spindles breaks, thus increasing their liability risks.
Manufacturers of spin bikes generally ensure that their own designs of pedal/cleat combinations are interchangeable. However, there is no interest on the part of these manufacturers to make their pedal/cleat designs compatible with any of their competitor's designs. This has created a serious inconvenience and difficulty in the use of spin bikes, which are used by a wide variety of cyclists and non-cyclists who are clients of a gym or exercise clubs. The clients of the gym or club wish to use their own particular brand of pedal/cleats and the gym can only offer a very limited selection.
Generally the exercise clubs offer the pedals sold to them with the exercise or spin bike by the particular spin bike manufacturer. To get around the problem, the gym may have to purchase spin bikes from a number of suppliers or change the pedals on their existing bikes to accommodate a wider variety of user preferences.
There is no known prior art in the field of pedal/cleat designs that fully addresses the pedal/cleat and spindle problems discussed above. In an earlier patent application, the present inventor disclosed a design for a flip-flop pedal, which is a first step to address the problem. The earlier application disclosed a pedal design which utilized both sides of the pedal surfaces so that one side matches a pedal type, embodied in the popular brand known as LOOK (the generic term for LOOK is a road bicycle style pedal). The other side of the pedal surface matches a pedal type embodied in the popular brand known as SPD (the generic term for SPD is a mountain bicycle style pedal). This earlier design of a LOOK/SPD (road/mountain) flip-flop pedal is disclosed and illustrated in the earlier application Ser. No. 08/923,022.
LOOK is a French company that makes a variety of products, one of which is a line of bicycle pedals and matching cleats. SPD is also a matching pedal/cleat design for bicycles made  by the Shimano Pedaling Device Co., of Japan. The present invention also includes special adapters that also accommodate cleat designs produced and sold by the SPEEDPLAY Company of San Diego, Calif. and in particular their cleat designs known as SPEEDPLAY X-Pedal (generic term is a road style pedal) and SPEEDPLAY Frog (generic term is a mountain style pedal). By this combination of flip-flop pedal and adapters, bicycles and mainly spin-bikes fitted with the invention can accommodate a very large majority of cyclists and shoe cleat designs.
In the art there is a special pedal adapter sold by a manufacturer called INSTEP (road) that fits onto both a LOOK (road) and an SPD (mountain) style pedal. The INSTEP (road) brand adapter is made by Winwood Company of Denver, Colo. Thus a cyclist wearing running shoes which do not have any bicycle shoe type sole cleats, can lock his running shoe into place on the INSTEP (road) adapter which in turn is mounted on a spin bike with a LOOK (road) style pedal. In this manner, a cyclist wearing running shoes can use a stationary spin bike, which are fitted with LOOK or SPD style pedals (road or mountain). This INSTEP (road) adapter is an attempt to address part of the problem discussed above, but does not take it to the level of invention described in the present application. Further, the INSTEP (road) adapter is essentially a toe-strap design and so represents a step backwards to the early unsatisfactory toe-strap designs used on bicycles many years ago.
FIG. 8a is a prior art top plan view of a standard LOOK (road) style shoe cleat that is attached to the sole of a cyclist's shoe. Three rectangular holes (221, 222, 223) are used to attach the cleat to the shoe sole (not shown). The top surface (288) of the shoe cleat is curved to fit the typical cycling shoe sole. All three rectangular holes have a recessed edge (227) which accommodates a rectangular washer (252 in FIG. 8b). One central rectangular hole (225) is used to hold a rubber bumper (not shown) which stops the cleat from rattling when loosely fitted to the sole of the cyclist's shoe. The front tongue (224) of the cleat fits under the front recess (202 in FIGS. 7a and 7b). The rear tongue (226) of the cleat fits under the spring-loaded  retaining plate (204 in FIGS. 7a and 7b).
FIG. 8b is a prior art exploded and cross-sectional view taken along line 8b—8b of the standard LOOK (road) style shoe cleat shown in FIG. 8a. The front and rear tongues (224 and 226) are shown. Three retaining washers (252 only one is shown) fit in the recesses (227) shown in FIG. 8a. Three screws (250 only one is shown) hold the cleat in place on the cycling shoe (not shown) by passing through the washers (252) and through the cleat holes (221, 222, 223 in FIG. 8a) and engaging in threaded holes in the base of the cycling shoe (not shown).
FIG. 11 is a view of a prior art INSTEP LOOK (road) style Pedal Adapter. The adapter body (300) is similar in shape to a standard LOOK (road) style cleat (FIGS. 8a and 8b), with a front tongue (306) and a rear tongue (305) identical to the front and rear tongues of a LOOK (road) style cleat. Thus the INSTEP (road) adapter can be locked onto a LOOK (road) style pedal. The toe-straps (301) are connected to an arch strap (302) through a common connector plate (307). The arch strap (302) is attached to the adapter body (300) in an adjustable manner (not shown). The cyclist inserts his running shoe into the cage consisting of the toe-straps and the arch strap and the upper surface (308) of the adapter base (300), thus forming an attachment between his running shoe and the INSTEP (road) adapter, which in turn, is connected to the pedal.
Referring to FIG. 12, there is shown a prior art of a first conventional type bicycle pedal 500 which is known in the art as LOOK bicycle pedal. This first prior art bicycle pedal 500 includes a toe or first retaining section 501, a rear or second spring-loaded plate 502 and a threaded spindle connector 503 which is connected to the bicycle pedal crank (not shown). The toe retaining section 501 holds the front 224 of a prior art of a first conventional type shoe cleat (see FIG. 8a) while the rear spring-loaded plate 502 moves away from the body of the pedal when the first prior art shoe cleat is inserted and the rear spring-loaded plate snaps back to lock the shoe cleat on the pedal 500. 
Referring to FIGS. 13 and 14, there is shown a prior art of a second conventional type bicycle pedal 504 which is known in the art as SPD bicycle pedal. This second prior art bicycle pedal 504 includes a front tongue recess 505, a rear tongue spring-loaded plate 506 and a threaded spindle connector 507 which is connected to the bicycle pedal crank (not shown). The spring-loaded retaining plate 506 is held in place by a winding spring 508 and secured to the body of the pedal 504 by a bolt 509. Referring to FIG. 23, a front tongue 512 of a second prior art type shoe cleat 510 is first inserted into the front tongue recess 505 and then the rear tongue 514 of the second prior art shoe cleat 510 pushes against the spring-loaded plate 506, causing the plate 506 to move away from the body of the pedal and once in place the spring-loaded retaining plate 506 moves back into position and securely locks the shoe cleat to the pedal 504.
Referring to FIG. 15, there is shown a prior art of a third conventional type bicycle pedal 516 which is known in the art as SPEEDPLAY “X” bicycle pedal. This second prior art bicycle pedal 516 includes a circular base 518, a metal bow-tie shaped plate 520 which is mounted to the base 518 and held by two screws 522, two grooves 524 located on opposites and parallel to a threaded spindle connector 526 which is connected to the bicycle pedal crank (not shown). Referring to FIG. 24, there is shown a prior art of a third conventional type shoe cleat 528 which correspondingly matches with the third prior art bicycle pedal 516. The shoe cleat 528 includes a circular shaped recess 530 which correspondingly matches the circular base 518 of the third prior art bicycle pedal 516 and two opposite parallel rods 532 almost extending the diameter of the recess 530. The third prior art shoe cleat is positioned onto of the third prior art bicycle pedal 516 such that the recess 530 encompass the base 518 and then the two parallel rods 532 engage with the two grooves 524 to secure the third prior art shoe cleat528 to the third prior art pedal 516.
Referring to FIG. 16, there is shown a prior art of a fourth conventional type bicycle pedal 534 which is known in the art as SPEEDPLAY frog bicycle pedal. This fourth prior art bicycle pedal 534 includes a circular metal ring 536 mounted and secured to a protruding base  538 by two screws 540, and a threaded spindle connector 537 which is connected to the bicycle pedal crank (not shown). A sloped ramp 542 is formed with the protruding base 538, which allows disengagement of the fourth prior art shoe cleat 544 shown in FIG. 25. When the cyclist rotates his or her shoe toward the bicycle's frame, two protruding lugs 546 on each side of the metal ring 536 are engaged by a pair of retaining flanges 548 to secure the fourth prior art shoe cleat 544 (see FIG. 25) thereto. A stopping flange 550 is also provided and engages with the sloped ramp 543 to stop the rotation of the fourth prior art shoe cleat 544, thereby fastening the fourth prior art shoe cleat to the fourth prior art bicycle pedal.
Referring to FIG. 17, there is shown a prior art of a fifth conventional type bicycle pedal 552 which is known in the art as BE-BOP bicycle pedal. This fifth prior art bicycle pedal 552 includes a pair of spaced apart opposite generally circular flanges 554 which form the attachment mechanism of the pedal, and a threaded spindle connector 547 which is connected to the bicycle pedal crank (not shown) and sandwiched between the circular flanges 554. Referring to FIG. 26, there is shown a prior art of a fifth conventional type shoe cleat 556 which correspondingly matches with the fifth prior art bicycle pedal 552. The shoe cleat 556 includes a circular shaped recess 558 which correspondingly matches with either one of the pair of circular flanges 554 of the fifth prior art bicycle pedal 552. The fifth prior art shoe cleat 552 is positioned onto of the fifth prior art bicycle pedal 516 such that the two opposite flanges 560 engage with the circular flange 554 of the fifth prior art bicycle pedal to secure the fifth prior art shoe cleat 556 to the fifth prior art pedal 552. 